The candidate is an established scientist in the medical device field, who seeks to retool in fundamental auditory neurobiology and redirect his career back to hearing science. Multi-unit and field potential-derived current source density mapping will be used to study the spatial and temporal properties of the synaptic drive and post-synaptic activity of neuronal populations in chicken Nucleus Laminaris (NL). Localized activity in a tuned population of coincidence detectors is assumed to provide a "place code" for the location of a sound based on interaural timing differences (ITD). In vitro brain slices and in vivo recordings are used as preparations for spatiotemporal mapping experiments to detail the interaural timing difference ITD topography in NL. We propose to identify the contribution of GABAergic input to the spatiotemporal topographic patterns. Neuronal excitation patterns are assessed with spatial profiles (1-D) or contours (2-D) extracted from space-time maps of multi-unit activity and the timing and distribution of current sources and sinks are defined with maps of field potentials, processed with current source density (CSD) analysis. [unreadable] [unreadable] [unreadable]